In a game device, processing is executed every predetermined time period. For example, the processing to be executed every predetermined time period in the game device includes processing of updating game situation data indicating the situation of a game and processing of updating a game screen based on the updated game situation data. For example, in the case of a game device for executing a sport game in which a moving object (for example, ball or puck) is used, the following items of processing are alternately executed. Those items of processing are processing of updating state data indicating the state (for example, position) of a player character or a moving object and processing of updating the game screen based on the updated state data of the player character or the moving object.
In general, the interval at which processing is executed in the game device is set in accordance with the system of a display device for displaying the game screen. For example, in a case where the game screen is displayed on a television set compliant with the National Television System Committee (NTSC) system, the processing is executed every 1/60th of a second (or 1/30th of a second). On the other hand, for example, in a case where the game screen is displayed on a television set compliant with the Phase Alternating Line (PAL) system, the processing is executed every 1/50th of a second (or 1/25th of a second).